-- add to NimbleClient.h/cpp

virtual void onPassKeyDisplay(NimBLEConnInfo& connInfo);
-- modify NimbleClient.cpp
Add the conditional statement event->passkey.params.action == BLE_SM_IOACT_DISP to the case BLE_GAP_EVENT_PASSKEY_ACTION: block in NimBLEClient::handleGapEvent().
-- add to NimbleDevice.h/cpp
static bool injectDisplayPassKey(const NimBLEConnInfo& peerInfo, uint32_t pin);

Author: inclusus

src/NimBLEClient.cpp

@@ -1205,9 +1205,12 @@ int NimBLEClient::handleGapEvent(struct ble_gap_event* event, void* arg) {
                 // pClient->onOobPairingRequest(pkey.oob);
                 // rc = ble_sm_inject_io(event->passkey.conn_handle, &pkey);
                 // NIMBLE_LOGD(LOG_TAG, "ble_sm_inject_io result: %d", rc);
-            } else if (event->passkey.params.action == BLE_SM_IOACT_INPUT || event->passkey.params.action == BLE_SM_IOACT_DISP) {
+            } else if (event->passkey.params.action == BLE_SM_IOACT_INPUT) {
                 NIMBLE_LOGD(LOG_TAG, "Enter the passkey");
                 pClient->m_pClientCallbacks->onPassKeyEntry(peerInfo);
+            } else if (event->passkey.params.action == BLE_SM_IOACT_DISP) {
+                NIMBLE_LOGD(LOG_TAG, "Display the passkey");
+                pClient->m_pClientCallbacks->onPassKeyDisplay(peerInfo);
             } else if (event->passkey.params.action == BLE_SM_IOACT_NONE) {
                 NIMBLE_LOGD(LOG_TAG, "No passkey action required");
             }
@@ -1298,6 +1301,11 @@ void NimBLEClientCallbacks::onPassKeyEntry(NimBLEConnInfo& connInfo) {
     NimBLEDevice::injectPassKey(connInfo, 123456);
 } // onPassKeyEntry
 
+void NimBLEClientCallbacks::onPassKeyDisplay(NimBLEConnInfo& connInfo) { //@@hjlee
+    NIMBLE_LOGD(CB_TAG, "onPassKeyEntry: default: 123456");
+    NimBLEDevice::injectDisplayPassKey(connInfo, 123456);
+} // onPassKeyEntry
+
 void NimBLEClientCallbacks::onAuthenticationComplete(NimBLEConnInfo& connInfo) {
     NIMBLE_LOGD(CB_TAG, "onAuthenticationComplete: default");
 } // onAuthenticationComplete

src/NimBLEClient.h

@@ -186,6 +186,7 @@ class NimBLEClientCallbacks {
      * @param [in] connInfo A reference to a NimBLEConnInfo instance containing the peer info.
      */
     virtual void onPassKeyEntry(NimBLEConnInfo& connInfo);
+    virtual void onPassKeyDisplay(NimBLEConnInfo& connInfo);
 
     /**
      * @brief Called when the pairing procedure is complete.

src/NimBLEDevice.cpp

@@ -1268,6 +1268,12 @@ bool NimBLEDevice::injectPassKey(const NimBLEConnInfo& peerInfo, uint32_t passke
     return rc == 0;
 }
 
+bool NimBLEDevice::injectDisplayPassKey(const NimBLEConnInfo& info, uint32_t passkey) {
+    ble_sm_io pkey{.action = BLE_SM_IOACT_DISP, .passkey = passkey};
+    int rc = ble_sm_inject_io(info.getConnHandle(), &pkey);
+    return rc == 0;
+}
+
 /**
  * @brief Inject the provided numeric comparison response into the Security Manager.
  * @param [in] peerInfo Connection information for the peer.

src/NimBLEDevice.h

@@ -174,6 +174,7 @@ class NimBLEDevice {
 # if MYNEWT_VAL(BLE_ROLE_PERIPHERAL) || MYNEWT_VAL(BLE_ROLE_CENTRAL)
     static bool injectConfirmPasskey(const NimBLEConnInfo& peerInfo, bool accept);
     static bool injectPassKey(const NimBLEConnInfo& peerInfo, uint32_t pin);
+    static bool injectDisplayPassKey(const NimBLEConnInfo& peerInfo, uint32_t pin);
 # endif
 
 # if MYNEWT_VAL(BLE_ROLE_BROADCASTER)